UK Wind-Generated Electricity on a fairly windy night

[JohnW2]

We recently had a discussion about the sources of UK electricity, mainly in relation to gas, and I suggested that (I meant during 'high demand' times of day), gas currently often accounts for around a half, or more, of the electricity being generated.

Turning to the lowest demand period of the day, and accepting that there is probably appreciably above-average wind today, I was quite impressed to see this recently (about 3.30 am) ...

Kind Regards, John

 

[big-all]

whilst it looks very impressive we need to know how much lower the demand is because off companies shutting down or supressing demand because high energy costs ??

 

[flameport]

For the same day and time for previous years (last Tuesday in October at 3.30am), demand rounded up to the nearest GW was
2009 = 27GW
2010 = 31GW
2011 = 28GW
2012 = 29GW
2013 = 25GW
2014 = 25GW
2015 = 25GW
2016 = 26GW
2017 = 25GW
2018 = 27GW
2019 = 27GW
2020 = 24GW
2021 = 23GW

The general trend for demand has been downwards for the last 20 years or so.
Variations overnight are mostly due to the weather, demand increases if the weather is cooler.

The main difference in 2009/2010 was that 75% of it was generated from coal and gas.

 

[JohnW2]

whilst it looks very impressive we need to know how much lower the demand is because off companies shutting down or supressing demand because high energy costs ??

I'm not sure whether you are talking about changes in demand over recent years or the last few weeks. As flameport has shown the long-term downward trend has been pretty modest. From flameport's figures, the average daily demand (for 26th October) for the three years 2009-2011 was 28.7 GW and for years 2019-2021 was 24.7 GW - a reduction of about 14% over 10 years, equating to a de-compounded reduction of just over 1% per year. I cannot tell you what has happened in recent weeks.

Anyway, apart from the matter of total demand, I remain impressed by the proportion of electricity that we are managing to generate from wind on a fairly windy day. The figures I posted last night (with 52.5% coming from wind) related to a time when total demand was about 22.5 GW. A few minutes ago (i.e. a bit after 1pm) the total demand was, at 33.5 GW about 50% higher than that, but the proportion of electricity being generated from wind was still about 25% greater than the proportion being generated from gas. It's obviously often not as windy as it is today, but I'm nevertheless fairly impressed.

Kind Regards, John

 

[Harry Bloomfield]

Turning to the lowest demand period of the day, and accepting that there is probably appreciably above-average wind today, I was quite impressed to see this recently (about 3.30 am) ...

Little gas generation being needed because it was unseasonably warm outside. What do we do when the weather is cold and the wind is not blowing?

 

[JohnW2]

The general trend for demand has been downwards for the last 20 years or so.

Indeed - but as I've just written, that downward trend has been pretty modest - about 1% p.a. over the past decade.

Variations overnight are mostly due to the weather, demand increases if the weather is cooler.

Undoubtedly true - but would I be right in thinking that that will be partially compensated by the fact that, in the UK, cooler weather tends to be associated with more wind?

Kind Regards, John

 

[JohnW2]

Little gas generation being needed because it was unseasonably warm outside. What do we do when the weather is cold and the wind is not blowing?

I'm not sure that 'unseasonably' is very relevant - it is at least as warm outside for a very appreciable proportion of every year as it is today. It goes without saying that demand will rise when weather is very cold, and that will always e an (unpredictable) problem.

However, as I've acknowledged, generation from wind requires appreciable amounts of wind, and that won't always be the case - but I'm still impressed by the figures I'm seeing when winds are not exceptionally high.

Kind Regards, John

 

[Harry Bloomfield]

However, as I've acknowledged, generation from wind requires appreciable amounts of wind, and that won't always be the case - but I'm still impressed by the figures I'm seeing when winds are not exceptionally high.

When the wind becomes exceptionally high, they have to feather the generators, so 'high' is not necessarily useful where wind generation is concerned.

 

[EFLImpudence]

would I be right in thinking that that will be partially compensated by the fact that, in the UK, cooler weather tends to be associated with more wind?

I don't think you are right in thinking that.

 

[Harry Bloomfield]

Undoubtedly true - but would I be right in thinking that that will be partially compensated by the fact that, in the UK, cooler weather tends to be associated with more wind?

No, when it gets really cold, the air tends to also be quite calm. Calm air is advantageous so far as the energy required is concerned, as there is less cooling of the home, but bad in that there is little to generate wind power.

 

[big-all]

For the same day and time for previous years (last Tuesday in October at 3.30am), demand rounded up to the nearest GW was
2009 = 27GW
2010 = 31GW
2011 = 28GW
2012 = 29GW
2013 = 25GW
2014 = 25GW
2015 = 25GW
2016 = 26GW
2017 = 25GW
2018 = 27GW
2019 = 27GW
2020 = 24GW
2021 = 23GW

The general trend for demand has been downwards for the last 20 years or so.
Variations overnight are mostly due to the weather, demand increases if the weather is cooler.

The main difference in 2009/2010 was that 75% of it was generated from coal and gas.

the average over the whole period 2009-2021 is 26.3 if you take the 5 years pre covid its 26 as opposed to 23.5 covid years so not a lot off difference at about 10% less or 11% more dependant on what way round you do it
so generation percentage would be slightly less in a normal year but non the less impressive

 

[scousespark]

Little gas generation being needed because it was unseasonably warm outside. What do we do when the weather is cold and the wind is not blowing?

Put your big coat on

 

[JohnW2]

I don't think you are right in thinking that.

No, when it gets really cold, the air tends to also be quite calm. Calm air is advantageous so far as the energy required is concerned, as there is less cooling of the home, but bad in that there is little to generate wind power.

You may both be right - that's why I asked the question.

I was thinking essentially 'seasonally', rather than on a day-to-day basis. Autumn and Winter are obviously cooler, and I thought (perhaps incorrectly) that they were also the times of year when significant wind was more common.

Anecdotally, I can certainly recall many a time when there were 'bitterly cold strong winds' (usually when I am forced to do something outdoors ).

Kind Regards, John

 

[JohnW2]

When the wind becomes exceptionally high, they have to feather the generators, so 'high' is not necessarily useful where wind generation is concerned.

Agreed, there is an 'optimum', rather than 'the more the better'.

I don't know how they do this, but I would have thought that it would be possible to 'partially feather' the blades when wind was very strong, so that they could function close to their 'maximum safe capability', without risk of damage. Is that not the case?

Kind Regards, John

 

[Harry Bloomfield]

I don't know how they do this, but I would have thought that it would be possible to 'partially feather' the blades when wind was very strong, so that they could function close to their 'maximum safe capability', without risk of damage. Is that not the case?

I don't know the answer to that - what little I do know is that some local ones are stopped/ not rotating, when the winds get high.